78213331 has 16 divisors (see below), whose sum is σ = 91119616. Its totient is φ = 65753856.

The previous prime is 78213313. The next prime is 78213337. The reversal of 78213331 is 13331287.

It is not a de Polignac number, because 78213331 - 2¹³ = 78205139 is a prime.

It is a super-2 number, since 2×78213331² = 12234650292231122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78213331.

It is not an unprimeable number, because it can be changed into a prime (78213337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85780 + ... + 86686.

It is an arithmetic number, because the mean of its divisors is an integer number (5694976).

Almost surely, 2^78213331 is an apocalyptic number.

78213331 is a deficient number, since it is larger than the sum of its proper divisors (12906285).

78213331 is a wasteful number, since it uses less digits than its factorization.

78213331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138.

The product of its digits is 3024, while the sum is 28.

The square root of 78213331 is about 8843.8301091778. The cubic root of 78213331 is about 427.6550394647.

The spelling of 78213331 in words is "seventy-eight million, two hundred thirteen thousand, three hundred thirty-one".